CHEMISTRY : Basic Atomic Structure

Subatomic Particle Charge

   Proton                             +1

   Electron                           -1

    Neutron                            0

Basic Atomic Structure ~The number of protons in an atom or ion determines what element it is.

For example, if a particle has 6 protons in it, it must be carbon. (relative molar mass of carbon is 12 , so 12 - 6 neutrons= 6 protons)

The atomic number of an atom or an ion is equal to its number of protons.

Atomic Number = Number of Protons

Example: potassium (K) in the periodic table, it has an atomic number of 19, meaning that all potassium atoms and all potassium ions contain 19 protons.

Atomic Mass Number = (number of Protons) + (number of Neutrons)

Example: A particle with 6 protons and an atomic mass number of 14 has 8 neutrons.


Ions = Charged Particles

~ Ions are formed when atoms gain or lose electrons. ~Positive ions (cations) are formed when a neutral atom loses electrons. ~Negative ions (anions) are formed when a neutral atom gains electrons. ~Metallic atoms tend to lose electrons to form positive ions (also known as cations). ~Nonmetallic atoms tend to gain electrons to form negative ions (a.k.a. anions).

Charge = (number of Protons) - (number of Electrons)

Example: A particle with 34 protons and 36 electrons has a charge of -2.


Isotopes are atoms of the same element that have a different number of neutrons. Therefore, isotopes have the following characteristics:

Isotopes have the same atomic number (same number of protons), but a different atomic mass number (a different number of neutrons). Isotopes behave the same chemically, because they are the same element. The only difference is that one is heavier than the other, because of the additional neutrons.

For example, carbon-12 and carbon-14 are both isotopes of carbon. Carbon-12 has 6 neutrons; carbon-14 has 8 neutrons.

Note by Nicole Ling
7 years, 1 month ago

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Subham bhuyan Bhuyan - 5 years, 4 months ago

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Thanks a lot

Taj Ali Khan - 6 years, 2 months ago

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Ripunjay Singh - 6 years, 3 months ago

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Irsha Haque - 6 years, 9 months ago

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# Isobars
Isobars are atoms of different elements that have the same number of nucleons (i.e. number of protons + number of neutrons). Correspondingly, isobars differ in the number of protons but have the same mass number. An example of a series of isobars would be 40-S, 40-Cl, 40-Ar, 40-K, and 40-Ca. The nuclei of these nuclides all contain 40 nucleons; however, they contain varying numbers of protons and neutrons.

# Isotones

Two elements are isotones if they have the very same neutron number, but different proton number. For example, boron-12 and carbon-13 nucleuses both contain 7 neutrons, and so are isotones.

There is also something called an isomer, however that's getting more into the structure of a chemical compound.

Just a bit of clarification on those terms. You'll know this feel when you study biology. Hahahahah...

#Let me just reiterate what those terms were.

Isotopes \Rightarrow Same number of protons, but different number of neutrons.

Isobar \Rightarrow Same number of (protons + neutrons) but different number of protons.

Isotone \Rightarrow Same number of neutrons but different number of protons.

Also, a way to visualise this mathematically (lol) isotope, isobar and isotone are like a set of chemical elements or compounds (in the case of an isomer).

Hope this helps and no one gets confused between them. ^^ And thank you for those contributing these notes.

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Thanks for you additional notes :)))

Nicole Ling - 7 years ago

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No worries, my pleasure. ^^

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It seems like Nicole will provide some helpful notes on Chemistry. She is my classmate and she is very interested in science especially Biology. Thumbs up for you Nicole!

Christopher Boo - 7 years, 1 month ago

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Thanks... But you are much better than me :)

Nicole Ling - 7 years, 1 month ago

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